Suspect Measles and Act Fast

Updated February 11, 2015 Editor's Note: The United States is currently experiencing a large, multistate outbreak of measles linked to an amusement park in California. The outbreak started in December 2014 and has spread to at least half a dozen other states. Healthcare providers treating patients with clinically compatible measles symptoms (like cough, coryza, or conjunctivitis) should consider measles, and should ask patients about vaccine status and recent travel or contact if measles is occurring in the community. More information

Hello. I'm Dr. Jane Seward, a medical epidemiologist at the Centers for Disease Control and Prevention (CDC). I'm speaking with you as part of the CDC Expert Commentary series on Medscape.

The United States is experiencing a record number of measles cases this year. From January 1 to June 6 of this year, 397 confirmed cases of measles have been reported. This is the highest annual number of reported measles cases in the United States in the past 20 years. Thus, it's important for healthcare providers to be able to recognize measles. This commentary will provide an overview of measles in the United States, a review of the signs and symptoms, and what to do if a healthcare provider suspects measles.

Before use of the measles vaccine in the United States, measles caused death and disability. In the decade before the measles vaccination program began, an estimated 3-4 million people in the United States were infected each year, of whom 400-500 died, 48,000 were hospitalized, and another 4000 developed chronic disability from measles encephalitis. Following the introduction of measles vaccine in the United States, measles cases declined dramatically. By 2000, owing to sustained high 2-dose measles-mumps-rubella (MMR) vaccine coverage in children, measles was declared eliminated from this country. Elimination does not mean gone forever; it means that the disease is no longer transmitted year-round in the United States. However, measles continues to be common in many other regions of the world, including Western Europe. Measles cases are imported into the United States every year, most commonly by US residents returning from travel abroad. These cases have led to 16 outbreaks and a record number of measles cases this year.

More than ever, healthcare providers need to be alert to the possibility of measles and know the signs and symptoms so they can detect cases accurately and early. Just this year, measles cases have been initially misdiagnosed as Kawasaki's disease, dengue, and scarlet fever, among other diseases. Misdiagnosis can result in delays in implementing critical measures to stop measles from spreading. Healthcare providers should consider measles in the differential diagnosis of patients with clinically compatible symptoms.

Let's review the clinical presentation of measles. The measles prodrome starts 3-4 days before the rash. The prodrome is characterized by a high fever that can run 105º F or higher and by the "3 C's": cough, coryza (runny nose), and conjunctivitis. Towards the end of the prodrome, Koplik's spots may appear inside the cheeks. These are small, white spots, often on a reddened background. Following the prodrome, a maculopapular rash begins on the forehead and spreads downward to the feet, also affecting the palms of the hands and the soles of the feet. The measles rash gradually recedes, fading first from the face and last from the thighs and feet. The patient may recover completely or may suffer from complications that can be severe, including pneumonia and encephalitis. A complication that may present about 10 years after a case of acute measles is subacute sclerosing panencephalitis (SSPE). This isa very rare, but fatal, degenerative disease of the central nervous system. Measles in the United States can still result in death. Between 1987 and 2000, the case fatality rate across the United States was 3 deaths for every 1000 measles cases.

Jane Seward, MD, obtained her medical degree from the University of Western Australia, her clinical training in pediatrics and infectious diseases at Tulane University, and her MPH in epidemiology from Emory University. Her public health career has spanned both domestic and international arenas in the fields of maternal and child health, birth defects, nutrition, and immunizations. The main focus of her work at CDC has been domestic vaccine programs with particular emphasis on measles, mumps, rubella, varicella, and herpes zoster. She has also provided technical assistance to countries on a variety of vaccine program issues, including measles outbreaks, introduction of new vaccines, and routine EPI. She is an internationally recognized varicella and immunization policy expert. She is currently Deputy Director in the Division of Viral Diseases, National Center for Immunizations and Respiratory Diseases, CDC.